The present invention generally relates to semiconductor device manufacturing, and more particularly to the elimination of defects in long Aspect Ratio Trapping (ART) trench structures.
The preparation of epitaxial layers on various substrates is an important field in modern materials science and technology. Such films are applied for example in protective coatings, thin film devices, semiconducting devices, laser diodes, sensors, for data storage devices, and for mounting organic, including biological layers onto suitable substrates. The term “epitaxial” means the ordered growth of a material on the surface of a substrate or another layer, such that the crystalline properties and orientation of the deposited material reflects the orientation and crystalline structure of the substrate. Thus epitaxial deposition processes provide means to form thin specifically oriented crystalline layers.
A problem in epitaxial deposition is one of lattice mismatch or misfit. Lattice mismatch occurs when the epitaxy layer and the seed layer have different lattice constants. Deviations of less than 1 percent readily result in structural defects, including various types of dislocation, and the built-up strain in the epitaxy layer.